Heat exchanger header

ABSTRACT

The invention concerns a header (3) for a heat exchanger (1) comprising: a header plate (4) comprising orifices intended to receive tubes (2), said header plate (4) comprising a peripheral groove (42), a compressible gasket (44) arranged within the peripheral groove (42), a cover (8) covering the header plate (4) and comprising lateral walls (81) that are inserted into the peripheral groove (42) and compress the gasket (44), the lateral walls (81) of the cover (8) comprising projecting retaining elements (82) that come to bear on the header plate (4).

The invention concerns a heat exchanger header and, more specifically, a header comprising a compressible gasket arranged between a header plate and a cover.

Heat exchanger headers generally comprise a header plate through which tubes pass and a cover covering the header plate in order to form a chamber in which a heat transfer fluid can circulate. The header plate generally comprises a peripheral groove inside which a gasket is positioned. The edges of the cover are inserted into the peripheral groove in order to compress the gasket.

However, the attaching of the cover to the header plate, in particular by crimping, can cause the gasket to be compressed excessively into the peripheral groove, which can result in it being damaged and thus increase the risk of leaks over time.

One of the aims of the present invention is therefore to at least partially overcome the problems of the prior art and propose a header and a heat exchanger with an improved connection between the cover and the header plate.

The present invention therefore concerns a header for a heat exchanger comprising:

-   -   a header plate comprising orifices intended to receive tubes,         said header plate comprising a peripheral groove,     -   a compressible gasket arranged within the peripheral groove,     -   a cover covering the header plate and comprising lateral walls         that are inserted into the peripheral groove and compress the         gasket,

the lateral walls of the cover comprising projecting retaining elements that come to bear on the header plate.

These retaining elements form stops and prevent the cover and, more specifically, the ends of the lateral walls of same, from being pressed beyond a certain limit into the peripheral groove. These retaining elements allow the gasket 44 to be compressed sufficiently to provide sealing while ensuring that it is not compressed excessively, which could damage it.

According to one aspect of the invention, the header plate has a generally rectangular shape with two long sides and two short sides, the retaining elements bearing simultaneously on the two long sides and/or the two short sides of said header plate 4.

According to another aspect of the invention, the retaining elements are produced on the outer face of the lateral walls and come to bear on the outer rim of the peripheral groove.

According to another aspect of the invention, the outer rim of the peripheral groove comprises crimping lugs and the retaining elements come to bear between two crimping lugs.

According to another aspect of the invention, the retaining elements are produced on the inner face of the lateral walls and come to bear on the inner rim of the peripheral groove.

According to another aspect of the invention, on a given side of the header plate, the cover comprises a single continuous retaining element along the length of said side of the header plate.

According to another aspect of the invention, on a given side of the header plate, the cover comprises at least two local retaining elements distributed along the length of said side of the header plate.

According to another aspect of the invention, the local retaining elements are arranged so as to bear on the header plate opposite the spaces between the orifices of said header plate.

According to another aspect of the invention, the retaining elements are integral with the cover.

The present invention also concerns a heat exchanger comprising a header as previously described.

Other features and advantages of the invention will become clearer on reading the description that follows, provided as an illustrative and non-limiting example, and viewing the appended drawings in which:

FIG. 1 shows a schematic view of a heat exchanger,

FIG. 2 shows a schematic cross-sectional view of the header of the heat exchanger of FIG. 1,

FIG. 3 shows a perspective view of the connection between the cover and the header plate according to a first embodiment,

FIG. 4 shows a cross-sectional perspective view of the connection between the cover and the header plate according to a second embodiment,

FIG. 5 shows a cross-sectional perspective view of the connection between the cover and the header plate according to a variant of the second embodiment,

FIG. 6 shows a perspective view of the connection between the cover and the header plate according to another variant of the second embodiment.

The elements that are identical in the different figures have been given the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference concerns the same embodiment, or that the features apply only to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

In the present description, certain elements or parameters may be numbered, for example as a first element or a second element, as a first parameter and a second parameter, or indeed a first criterion and a second criterion, etc. The purpose of this numbering is simply to differentiate between and designate elements, parameters or criteria that are similar but not identical. This numbering does not imply priority of one element, parameter or criterion over another, and such designations can easily be interchanged without departing from the context of the present description. Nor does this numbering imply an order in time, for example in terms of appraising such or such criteria.

FIG. 1 shows a heat exchanger 1 having a generally parallelepiped shape and comprising a bundle formed from a plurality of tubes 2 inside which a first heat transfer fluid can flow. The tubes 2 have an oval or oblong cross section, defined by a major axis and a minor axis, and are arranged parallel to each other so as to form a row of tubes 2. Between the tubes 2, spacers 6 are arranged, acting as interference devices and increasing the surface area for the exchange of heat with a second heat transfer fluid passing between the tubes 2.

The tubes 2 and the spacers 6 are generally made from metal. The tubes 2 and the spacers 6 forming the bundle can be attached together by brazing. The spacers 6 are then referred to as inserts and are, for example, corrugated or crenellated strips positioned between the tubes 2 and attached to said tubes 2 by brazing. This is then referred to as a brazed bundle. The tubes 2 and the spacers 6 forming the bundle can be attached together by mechanical attachment. The spacers 6 are then referred to as fins and are, for example, metal plates comprising orifices through which the tubes 2 pass. The tubes 2 are attached in these orifices by expanding their diameter. This is then referred to as a mechanical bundle.

The heat exchanger 1 also comprises two headers 3 or water tanks, one header 3 being arranged at each end of the tubes 2. These headers 3 each comprise a header plate 4 and a cover 8 that covers the header plate 4 and closes the header 3 in such a way as to form a chamber 30 (shown in FIG. 2) in which the first heat transfer fluid can circulate. These headers 3 are used to collect and/or distribute the first heat transfer fluid in order for it to circulate in the tubes 2.

The header plate 4 sealingly connects the header 3 and the bundle of tubes 2. Moreover, the header plate 4 can have a generally rectangular shape with two long sides and two short sides. The header plate 4 also comprises a plurality of orifices shaped to match the shape of the cross section of the tubes 2 and capable of receiving the ends of the tubes 2. The orifices are therefore arranged in a row parallel to the long side of the header plate 4.

The tubes 2 can be sealingly attached to the header plate 4 by brazing, in which case the heat exchanger in question is a brazed heat exchanger. The tubes 2, the spacers 6 and the header plates 4 can be made from a metal material, in particular aluminum or aluminum alloy, in order to provide good thermal conductivity and allow brazing. The cover 8 can be made from plastic material.

According to an alternative, the tubes 2 can be attached to the header plate 4 mechanically with the use of a gasket, in which case the heat exchanger in question is a mechanical heat exchanger. When using this attachment method, the entire header 3, i.e. the header plate 4 and the cover 8, can be made from plastic material.

As shown in FIG. 2, which is a schematic cross-sectional view of a header 3, the header plate 4 comprises a peripheral groove 42 around its entire periphery. The cover 8 comprises lateral walls 81 that are inserted into the peripheral groove 42 and compress a gasket 44 inserted into the peripheral groove 42 in order to provide sealing. The cover 8 can, in particular, be held against the header plate 4 by crimping lugs 43 arranged on the outer rim 41 of the peripheral groove 42 and folded over a shoulder 80 of the cover 8 arranged at the ends of the lateral walls 81 of same. In this instance, the outer rim 41 of the peripheral groove 42 refers to the rim that is on the outer side of the header 3, i.e. furthest away from the orifices of the header plate 4.

As shown in FIGS. 3 to 6, the lateral walls 81 of the cover 8 comprise projecting retaining elements 82 that come to bear on the header plate 4.

These retaining elements 82 form stops and prevent the cover 8 and, more specifically, the ends of the lateral walls 81 of same, from being pressed beyond a certain limit into the peripheral groove 42. These retaining elements 82 are arranged on the lateral walls 81 of the cover 8 at a certain distance from the ends of these lateral walls 81 such that the gasket 44 is compressed sufficiently to provide sealing while ensuring that it is not compressed excessively, which could damage it.

If the header plate 4 has a generally rectangular shape with two long sides and two short sides, the retaining elements 82 come to bear simultaneously on its two long sides and/or its two short sides in order to keep the cover 8 pressed on.

Preferably, these retaining elements 82 are integral with the cover 8 and can thus be produced at the same time as the cover 8, for example by molding if the cover 8 is made from plastic material.

According to a first embodiment shown in FIG. 3, the retaining elements 82 are formed on the outer face of the lateral walls 81. The retaining elements 82 can therefore be a shoulder of the lateral wall 81 that comes to bear on the outer rim 41 of the peripheral groove 42. In this instance, the outer face refers to the face of the cover 8 that is on the outer side of the header 3, i.e. furthest away from the chamber 30.

When the cover 8 is attached by crimping and the header plate 4 comprises crimping lugs 43 on the outer rim 41 of the peripheral groove 42, the retaining elements 82 then come to bear between the crimping lugs 43 in order not to hinder the crimping. As shown in FIG. 3, the retaining elements 82 can therefore bear on the outer rim 41 of the peripheral groove 42 at a cutout 45 provided between two crimping lugs 43 before they are folded onto the shoulder 80 of the cover 8.

According to a second embodiment shown in FIGS. 4 to 6, the retaining elements 82 are formed on the inner face of the lateral walls 81.

The retaining elements 82 can therefore be shoulders of the lateral wall 81 that come to bear on the inner rim 41 of the peripheral groove 42 and come to bear on the inner rim of the peripheral groove 42. In this instance, the inner face and the inner rim refer to the face of the cover 8 and the rim of the peripheral groove 42 that are on the inner side of the header 3, i.e. that which is inside the chamber 30.

The retaining elements 82 can also be a beveled part of the lateral wall 81 that comes to bear on the inner rim of the peripheral groove 42 and that immobilizes the end of the lateral wall 81 against the outer rim of the peripheral groove 42.

The fact that the retaining elements 82 are on the inner face of the lateral walls 81 means the retaining elements 82 do not hinder the attachment of the cover 8, in particular the crimping, and avoids problems of positioning the cover 8 when assembling the header 3.

FIG. 4 shows a first variant of the second embodiment in which, on a given side of the header plate 4, the cover 8 comprises a single retaining element 82. This retaining element 82 is continuous along the length of the side of the header plate 4 in order to evenly distribute the pressure applied by attaching the cover 8 and thus prevent local weakening of the cover 8 in the peripheral groove 42 when said cover 8 is attached.

FIG. 5 shows a second variant of the second embodiment in which, on a given side of the header plate 4, the cover 3 comprises at least two local retaining means 82 distributed along the length of said side of the header plate 4.

On the long sides of the header plate 4, the retaining elements 82 can bear both opposite the orifices of the header plate 4 and the spaces between two orifices if there is a sufficient distance between the edge of these orifices and the inner rim of the peripheral groove 42, as shown in FIG. 5.

If there is not a sufficient distance between the edge of the orifices of the header plate 4 and the inner rim of the peripheral groove 42, as shown in FIG. 6, the local retaining elements 82 are arranged so as to bear on the header plate 4 opposite the spaces between the orifices of said header plate 4 and are inserted partially into these spaces. In order to evenly distribute the pressure applied by attaching the cover 8 and thus prevent local weakening of the cover 8 in the peripheral groove 42 when said cover 8 is attached, a retaining element 82 can be positioned opposite each tube orifice.

It can therefore be seen that, due to the presence of the retaining elements 82 preventing the cover 8 from being pressed too far into the peripheral groove 42, the gasket 44 cannot be compressed excessively, thus reducing the risk of damage to this gasket 44 over time and therefore the probability of leaks. 

1. A header for a heat exchanger comprising: a header plate comprising orifices intended to receive tubes, said header plate comprising a peripheral groove; a compressible gasket arranged within the peripheral groove; and a cover covering the header plate and comprising lateral walls that are inserted into the peripheral groove and compress the gasket, wherein the lateral walls of the cover comprise projecting retaining elements that come to bear on the header plate.
 2. The header as claimed in claim 1, wherein the header plate has a generally rectangular shape with two long sides and two short sides, the retaining elements coming to bear simultaneously on the two long sides and/or the two short sides of said header plate.
 3. The header as claimed in claim 2, wherein the retaining elements are produced on the outer face of the lateral walls and come to bear on the outer rim of the peripheral groove.
 4. The header as claimed in claim 3, wherein the outer rim of the peripheral groove comprises crimping lugs and the retaining elements come to bear between two crimping lugs.
 5. The header as claimed in claim 1, wherein the retaining elements are produced on the inner face of the lateral walls and come to bear on the inner rim of the peripheral groove.
 6. The header as claimed in claim 5, wherein on a given side of the header plate, the cover comprises a single continuous retaining element along the length of said side of the header plate.
 7. The header as claimed in claim 5, wherein on a given side of the header plate, the cover comprises at least two local retaining elements distributed along the length of said side of the header plate.
 8. The header as claimed in claim 7, wherein the local retaining elements are arranged so as to bear on the header plate opposite spaces between the orifices of said header plate.
 9. The header as claimed in claim 1, wherein the retaining elements are integral with the cover.
 10. A heat exchanger comprising: a header including: a header plate comprising orifices intended to receive tubes, said header plate comprising a peripheral groove; a compressible gasket arranged within the peripheral groove; and a cover covering the header plate and comprising lateral walls that are inserted into the peripheral groove and compress the gasket, wherein the lateral walls of the cover comprise projecting retaining elements that come to bear on the header plate.
 11. A header for a heat exchanger comprising: a header plate comprising orifices intended to receive tubes, said header plate comprising a peripheral groove; a compressible gasket arranged within the peripheral groove; and a cover covering the header plate and comprising lateral walls that are inserted into the peripheral groove and compress the gasket, wherein the lateral walls of the cover comprise projecting retaining elements that come to bear on the header plate, the projecting retaining elements forming stops that prevent ends of the lateral walls of the cover from being pressed beyond a limit into the peripheral groove. 